I had two left burners on, they are rated 9500 btu each. I used a 1/2" aluminum disc to distribute heat across the bottom stone, it was partially exposed to the two burners. I think cast iron will work better and will be cheaper too but require more maintenance.

I noticed form my last test that the MPO roof in the back has caved in word, about 1/4' at the back center. When I used only the two back burners, the heat was concentrated at the to back of MPO, the temperature between the back and the front of MPO was couple hundred degs difference. This can be fixed by beefing up the back end of MPO.

This issue will not occur with the usage of MPO on gas grills like mine.

The picture below from a test I done yesterday using thin copper sheet to cover the top stone, as you can seen, I experienced less browning... this need another thread.

I noticed form my last test that the MPO roof in the back has caved in word, about 1/4' at the back center. When I used only the two back burners, the heat was concentrated at the to back of MPO, the temperature between the back and the front of MPO was couple hundred degs difference. This can be fixed by beefing up the back end of MPO.

This issue will not occur with the usage of MPO on gas grills like mine.

The picture below from a test I done yesterday using thin copper sheet to cover the top stone, as you can seen, I experienced less browning... this need another thread.

Just to be clear...that small amount of metal flexing occurred only when the MPO was used on an indoor experimental plate that was set right on top of kitchen burner. MPO has been working flawlessly on out door grills.

On the grill, the entire body of MPO is exposed more or less to the same amount of heat. Even when I tested MPO on the gas stove top using all 4 burners, no problem, all 4 corners were exposed to heat (but there too much heat than the MPO vent can flow out, so there was too much heat comming from under MPO and getting my stove really hot.

But with only two burners, the heat from the burners was concentrated at the bak of the oven, which heated the back to a temperature much higher than the front. Which caused MPO back roof to flex down. Due to the temperature diference between the back and the front, Turning the pizza while baking is not enough in this cas, a turning stone mechanism is essential for baking to get even temperature all across the bottom stone and getting pizza exposed to the MPO back high temperature equqlly.

plus, the plate prevented some of the heat to escape when MPO is closed.